Which colors must now be placed alongside one another to produce a harmonious effect? The laws for this are founded on the peculiarity of the power of man's vision. The eye, demands to be satisfied, an accord of primary colors. Red requires to annihilate one sided irritation the two primary colors, yellow and blue. The secondary green is obtained by a combination of yellow and blue, for that reason green is the color demanded by red to please the eye. But there must be a contrast of colors, for instance light red and dark green or dark red and light green must be brought together. The same thing is the case with other primary colors. The primary color yellow demands the secondary purple, blue, the secondary orange, the tertiary color olive, the secondary orange, brownish red and green, brimstone yellow and violet.
The correct treatment of the shadow tone of a given color depends upon the knowledge of the laws of the annihilation of color effect. As in nature, a shadow is formed by obstructing the light, so in the technic of coloring the shadow is obtained by the annihilation of the light-color. By combination of a primary color with a harmonizing secondary color of equal strength, we obtain the right shadow tone of the first color. In this way, by experiments in mixing, the right shadow tones, which form in a multi-colored edge, the gradual transitions of primary colors can be easily detected.
THE COMB MARBLE.
THE COMB MARBLE.
(SEE [SPECIMEN PLATES].)
The comb or nonpareil marble belongs to those edges which are not so frequently used, although it is superior in brightness and variety of colors to other marbles, provided the combination of colors is a correct one and there are no entire blotches of the same color present. For the comb-marble in general use, four colors are mostly employed, namely black, blue, yellow and red. To these white is added, but not as a color, as it is formed by the stylus in drawing the colors.